{"id":{"repo_id":"bayreuth","oai_identifier":"oai:epub.uni-bayreuth.de:771"},"canonical_url":"https://search.dev.ndltd.org/etd/bayreuth/oai:epub.uni-bayreuth.de:771","repository":{"repo_id":"bayreuth","name":"Universität Bayreuth","base_url":"https://epub.uni-bayreuth.de/cgi/oai2"},"display":{"title":"Fused and spiro furanones from tetronic acid synthons: Oxa and azacycles featuring the butenolide ring","abstract":"Diverse 4-O-allyl tetronates were obtained by reaction of allyl (alpha-hydroxy)carboxylates with keteneylidenetriphenylphosphorane (Ph3PCCO) in a domino reaction (addition – Wittig olefination) and by direct allylation of tetronic acid via Fischer esterification. 3-Allyl tetronic acids were generated by Claisen rearrangement of 4-O-allyl tetronates under microwave conditions; a subsequent Conia reaction produced the corresponding spiro cyclopropane furan-2,4-diones. Nucleophilic ring opening with diverse alcohols converted the spiro cyclopropane furan-2,4-diones to 3-beta-alkyloxypropyltetronic acids. When using O-benzyl isourea for the 4-O-alkylation of 3-allyl tetronic acids, the 3-benzyl derivatives were also formed (five examples were prepared). The Mitsunobu reaction proved to be a better way for the 4-O-alkylation of 3-allyl tetronic acids. 3,3-Diallyldihydrofuran-2,4-diones with two identical allyl residues were obtained by Tsuji-Trost-type Pd-catalysed allylation of either 4-O-allyltetronates or 3-allyltetronic acids. Pd assisted allylation of sodium 3-allyltetronate with a second allyl acetate gave mixed derivatives as did the Claisen rearrangement of 4-O-allyl 3-allyltetronates under microwave conditions. 3,3-Diallyldihydrofuran-2,4-diones were converted to butanolides with 3,3-spirocyclopentenyl or 3,4-cycloalkanyl annulation by ring closing methathesis with Grubbs’ catalysts. Natural product pesthetoxin was prepared via a double Ph3PCCO addition to alpha-hydroxy benzyl octanoate, thus demonstrating the utility of keteneylidenetriphenylphosphorane as a C2O building block. Finally, (-)-3-epi-blastmycinolactol was prepared enantioselectively via double hydrogenation of 3-but-2-enyl tetronic acid.","abstract_html":"Diverse 4-O-allyl tetronates were obtained by reaction of allyl (alpha-hydroxy)carboxylates with keteneylidenetriphenylphosphorane (Ph3PCCO) in a domino reaction (addition – Wittig olefination) and by direct allylation of tetronic acid via Fischer esterification. 3-Allyl tetronic acids were generated by Claisen rearrangement of 4-O-allyl tetronates under microwave conditions; a subsequent Conia reaction produced the corresponding spiro cyclopropane furan-2,4-diones. Nucleophilic ring opening with diverse alcohols converted the spiro cyclopropane furan-2,4-diones to 3-beta-alkyloxypropyltetronic acids. When using O-benzyl isourea for the 4-O-alkylation of 3-allyl tetronic acids, the 3-benzyl derivatives were also formed (five examples were prepared). The Mitsunobu reaction proved to be a better way for the 4-O-alkylation of 3-allyl tetronic acids. 3,3-Diallyldihydrofuran-2,4-diones with two identical allyl residues were obtained by Tsuji-Trost-type Pd-catalysed allylation of either 4-O-allyltetronates or 3-allyltetronic acids. Pd assisted allylation of sodium 3-allyltetronate with a second allyl acetate gave mixed derivatives as did the Claisen rearrangement of 4-O-allyl 3-allyltetronates under microwave conditions. 3,3-Diallyldihydrofuran-2,4-diones were converted to butanolides with 3,3-spirocyclopentenyl or 3,4-cycloalkanyl annulation by ring closing methathesis with Grubbs’ catalysts. Natural product pesthetoxin was prepared via a double Ph3PCCO addition to alpha-hydroxy benzyl octanoate, thus demonstrating the utility of keteneylidenetriphenylphosphorane as a C2O building block. Finally, (-)-3-epi-blastmycinolactol was prepared enantioselectively via double hydrogenation of 3-but-2-enyl tetronic acid.","abstract_has_math":false,"creators":["Urbina-Gonzalez, Juan-Manuel"],"institution":"Universität Bayreuth","degree_name":null,"degree_level":"thesis.doctoral","degree_discipline":null,"degree_department":null,"school":null,"contributors":["Schobert, Rainer"],"advisors":[],"committee_chairs":[],"committee_members":[],"year":2006,"date_issued":"2006-07-11","date_published":"2006-07-11","updated_at":"2026-07-27T18:49:26Z","subjects":[],"languages":[],"rights":[],"rights_urls":[],"identifier_entries":[]},"links":{"outbound_url":"https://epub.uni-bayreuth.de/id/eprint/771/","outbound_label":"Repository record","outbound_source":"source_url"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor","label":"Contributor","values":["Schobert, Rainer"]},{"key":"dc:creator","label":"Author","values":["Urbina-Gonzalez, Juan-Manuel"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:publisher","label":"Institution","values":["Universität Bayreuth"]},{"key":"dc:type","label":"Dc Type","values":["doctoralThesis"]},{"key":"thesis:degree_level","label":"Degree Level","values":["thesis.doctoral"]},{"key":"thesis:institution_name","label":"Thesis Institution Name","values":["Universität Bayreuth"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description.abstract","label":"Abstract","values":["Diverse 4-O-allyl tetronates were obtained by reaction of allyl (alpha-hydroxy)carboxylates with keteneylidenetriphenylphosphorane (Ph3PCCO) in a domino reaction (addition – Wittig olefination) and by direct allylation of tetronic acid via Fischer esterification. 3-Allyl tetronic acids were generated by Claisen rearrangement of 4-O-allyl tetronates under microwave conditions; a subsequent Conia reaction produced the corresponding spiro cyclopropane furan-2,4-diones. Nucleophilic ring opening with diverse alcohols converted the spiro cyclopropane furan-2,4-diones to 3-beta-alkyloxypropyltetronic acids. When using O-benzyl isourea for the 4-O-alkylation of 3-allyl tetronic acids, the 3-benzyl derivatives were also formed (five examples were prepared). The Mitsunobu reaction proved to be a better way for the 4-O-alkylation of 3-allyl tetronic acids. 3,3-Diallyldihydrofuran-2,4-diones with two identical allyl residues were obtained by Tsuji-Trost-type Pd-catalysed allylation of either 4-O-allyltetronates or 3-allyltetronic acids. Pd assisted allylation of sodium 3-allyltetronate with a second allyl acetate gave mixed derivatives as did the Claisen rearrangement of 4-O-allyl 3-allyltetronates under microwave conditions. 3,3-Diallyldihydrofuran-2,4-diones were converted to butanolides with 3,3-spirocyclopentenyl or 3,4-cycloalkanyl annulation by ring closing methathesis with Grubbs’ catalysts. Natural product pesthetoxin was prepared via a double Ph3PCCO addition to alpha-hydroxy benzyl octanoate, thus demonstrating the utility of keteneylidenetriphenylphosphorane as a C2O building block. Finally, (-)-3-epi-blastmycinolactol was prepared enantioselectively via double hydrogenation of 3-but-2-enyl tetronic acid.","Durch eine Dominoreaktion von alpha-Hydroxy-allylestern mit Ketenylidentriphenylphosphoran und durch direkte Allylierung von Tetronsäure über die Fischer-Veresterung wurden diverse 4-O-Allyl-Tetronate synthetisiert. Aus diesen wurden durch Claisenumlagerung unter Mikrowellenbedingungen 3-Allyl-tetronsäuren hergestellt, welche durch eine anschließende Conia-Reaktion zu den entsprechenden Spirocyclopropylfuran-2,4-dionen reagierten. Durch nukleophile Ringöffnung mit verschiedenen Alkoholen konnten die Spirocyclopropylfuran-2,4-dione in 3-beta-Alkyloxypropyl-tetronsäuren umgewandelt werden. Anhand von fünf Beispielen konnte gezeigt werden, dass bei Einsatz von O-Benzyl-Isoharnstoff zur 4-O-Alkylierung von 3-Allyl-tetronsäuren auch 3-Benzyl Derivate gebildet wurden. Die Mitsunobureaktion erwies sich als der bessere Weg zur 4-O-Alkylierung von 3-Allyl-tetronsäuren. Mit Hilfe der Tsuji-Trost-artigen Palladium-katalysierten Allylierung von 4-O-Allyl- oder 3-Allyl-tetronsäuren konnten 3,3-Diallyldihydrofuran-2,4-dione gebildet werden. Wie bei der Claisenumlagerung von 4-O-Allyl-3-allyl-tetronaten ergab die Palladium-vermittelte Allylierung von 3-Allyl-tetronaten mit weiterem Allylacetat eine Mischung aus verschiedenen Derivaten. 3,3-Spiropentenyl oder 3,4-Cycloalkanyl-Annelierung durch „Ringschluss-Methathese“ von 3,3-Diallyldihydrofuran-2,4-dione mit Hilfe von Grubbs Katalysatoren führte zu Butanoliden. Die Synthese des Naturstoffs Pesthetoxin ist ein weiterer Beleg für die Vielseitigkeit von Ketenylidentriphenylphosphoran als C2O Baustein. (-)-3-epi-Blastmycinolactol wurde durch doppelte Hydrierung von 3-But-2-enyl-tetronsäure enantioselektiv synthetisiert."]},{"key":"dc:format.medium","label":"Dc Format Medium","values":["application/pdf"]},{"key":"dc:title","label":"Title","values":["Fused and spiro furanones from tetronic acid synthons: Oxa and azacycles featuring the butenolide ring"]}]}],"canonical_facts":{"dc:contributor":["Schobert, Rainer"],"dc:creator":["Urbina-Gonzalez, Juan-Manuel"],"dc:description.abstract":["Diverse 4-O-allyl tetronates were obtained by reaction of allyl (alpha-hydroxy)carboxylates with keteneylidenetriphenylphosphorane (Ph3PCCO) in a domino reaction (addition – Wittig olefination) and by direct allylation of tetronic acid via Fischer esterification. 3-Allyl tetronic acids were generated by Claisen rearrangement of 4-O-allyl tetronates under microwave conditions; a subsequent Conia reaction produced the corresponding spiro cyclopropane furan-2,4-diones. Nucleophilic ring opening with diverse alcohols converted the spiro cyclopropane furan-2,4-diones to 3-beta-alkyloxypropyltetronic acids. When using O-benzyl isourea for the 4-O-alkylation of 3-allyl tetronic acids, the 3-benzyl derivatives were also formed (five examples were prepared). The Mitsunobu reaction proved to be a better way for the 4-O-alkylation of 3-allyl tetronic acids. 3,3-Diallyldihydrofuran-2,4-diones with two identical allyl residues were obtained by Tsuji-Trost-type Pd-catalysed allylation of either 4-O-allyltetronates or 3-allyltetronic acids. Pd assisted allylation of sodium 3-allyltetronate with a second allyl acetate gave mixed derivatives as did the Claisen rearrangement of 4-O-allyl 3-allyltetronates under microwave conditions. 3,3-Diallyldihydrofuran-2,4-diones were converted to butanolides with 3,3-spirocyclopentenyl or 3,4-cycloalkanyl annulation by ring closing methathesis with Grubbs’ catalysts. Natural product pesthetoxin was prepared via a double Ph3PCCO addition to alpha-hydroxy benzyl octanoate, thus demonstrating the utility of keteneylidenetriphenylphosphorane as a C2O building block. Finally, (-)-3-epi-blastmycinolactol was prepared enantioselectively via double hydrogenation of 3-but-2-enyl tetronic acid.","Durch eine Dominoreaktion von alpha-Hydroxy-allylestern mit Ketenylidentriphenylphosphoran und durch direkte Allylierung von Tetronsäure über die Fischer-Veresterung wurden diverse 4-O-Allyl-Tetronate synthetisiert. Aus diesen wurden durch Claisenumlagerung unter Mikrowellenbedingungen 3-Allyl-tetronsäuren hergestellt, welche durch eine anschließende Conia-Reaktion zu den entsprechenden Spirocyclopropylfuran-2,4-dionen reagierten. Durch nukleophile Ringöffnung mit verschiedenen Alkoholen konnten die Spirocyclopropylfuran-2,4-dione in 3-beta-Alkyloxypropyl-tetronsäuren umgewandelt werden. Anhand von fünf Beispielen konnte gezeigt werden, dass bei Einsatz von O-Benzyl-Isoharnstoff zur 4-O-Alkylierung von 3-Allyl-tetronsäuren auch 3-Benzyl Derivate gebildet wurden. Die Mitsunobureaktion erwies sich als der bessere Weg zur 4-O-Alkylierung von 3-Allyl-tetronsäuren. Mit Hilfe der Tsuji-Trost-artigen Palladium-katalysierten Allylierung von 4-O-Allyl- oder 3-Allyl-tetronsäuren konnten 3,3-Diallyldihydrofuran-2,4-dione gebildet werden. Wie bei der Claisenumlagerung von 4-O-Allyl-3-allyl-tetronaten ergab die Palladium-vermittelte Allylierung von 3-Allyl-tetronaten mit weiterem Allylacetat eine Mischung aus verschiedenen Derivaten. 3,3-Spiropentenyl oder 3,4-Cycloalkanyl-Annelierung durch „Ringschluss-Methathese“ von 3,3-Diallyldihydrofuran-2,4-dione mit Hilfe von Grubbs Katalysatoren führte zu Butanoliden. Die Synthese des Naturstoffs Pesthetoxin ist ein weiterer Beleg für die Vielseitigkeit von Ketenylidentriphenylphosphoran als C2O Baustein. (-)-3-epi-Blastmycinolactol wurde durch doppelte Hydrierung von 3-But-2-enyl-tetronsäure enantioselektiv synthetisiert."],"dc:format.medium":["application/pdf"],"dc:publisher":["Universität Bayreuth"],"dc:title":["Fused and spiro furanones from tetronic acid synthons: Oxa and azacycles featuring the butenolide ring"],"dc:type":["doctoralThesis"],"thesis:degree_level":["thesis.doctoral"],"thesis:institution_name":["Universität Bayreuth"]},"updated_at":"2026-07-27T18:49:26Z"}